How can I achieve the following:

• Sheet1: has a range of cells A1:M13 which have conditional format rules: if text is exactly "1" (to "15" so 15 rules) → each number gives the cell a different background filling.
• Sheet2: I want do Conditional Formatting on range A1:M13 based on the cell values in Sheet1!A1:M13.

At the moment I have the following custom formula in conditional formatting:

=if((INDIRECT("Sheet1!A1:M13=1")))

What do I do wrong? Do I have to set format of Sheet1 to value=1 instead of text is exactly "1"?